Iran has told the United Nations nuclear watchdog that it will increase its nuclear enrichment capacity within the limits set by the 2015 agreement with world powers.
"A letter was submitted to the agency yesterday regarding the start of certain activities," nuclear chief Ali Akbar Salehi, a vice president and head of the Iranian Atomic Energy Organisation, said on Tuesday.
"If conditions allow, maybe tomorrow night at Natanz, we can announce the opening of the centre for production of new centrifuges" for uranium enrichment, he said, quoted by news agency Fars.
Mr Salehi stressed the announcement did not mean they will start assembling the centrifuges, and "does not violate the (2015 nuclear) agreement" between Tehran and world powers.
Under the 2015 agreement, Iran can build parts for the centrifuges as long as it does not put them into operation within the first decade.
Behrouz Kamalvandi, the spokesman for Iran's nuclear agency, was quoted by state television on Tuesday as saying a letter was submitted to the International Atomic Energy Agency detailing the move.
Iran's Supreme Leader, Ayatollah Ali Khamenei, had ordered the increase in a speech on Monday. He vowed that the country would preserve its nuclear programme despite the US withdrawal from the landmark 2015 accord.
Iran has said it has the option of resuming industrial-scale enrichment now that the US has withdrawn from the deal.
European signatories of the accord back the deal but have concerns about Iran’s ballistic missile programme and its influence in the Middle East. Iran says the two issues are non-negotiable.
Iran nuclear deal
Under the agreement with the US, France, Germany, Britain, Russia and China, Iran limited uranium enrichment capacity to satisfy the powers that it could not be used to develop atomic bombs.
In exchange, Iran received relief from sanctions, most of which were rescinded in January 2016.
The deal allows Iran to continue 3.67 per cent uranium enrichment, far below the roughly 90 per cent threshold of weapons-grade material. Before the deal was reached, Tehran enriched uranium to up to 20 per cent purity.
European leaders have moved to salvage the deal after US President Donald Trump's announcement of Washington's exit on May 8.
The US has warned European companies to stop doing business in Iran or face the threat of breaching new and tougher sanctions on the Islamic Republic.
Mr Trump cited evidence of a secret nuclear programme, announced by Israeli Prime Minister Benjamin Netanyahu, as a justification for stepping away from the deal.
The Israeli leader said Tuesday that the Iranian plan to increase its nuclear enrichment capacity was aimed at producing nuclear weapons to be used against Israel.
"Two days ago, Ayatollah Khamenei, Iran's supreme leader, stated his intention to destroy the State of Israel," Mr Netanyahu said in a video posted on social media.
On Sunday, Iran's supreme leader Ayatollah Ali Khamenei called Israel a "malignant cancerous tumour" that should be removed.
"Yesterday he explained how he would do it – by unlimited enrichment of uranium to create an arsenal of nuclear bombs."
The Israeli leader heads to Paris on Tuesday in an effort to win support from EU allies on Iran.
He will be hosted by President Emmuanuel Macron at the Elysee Palace on Tuesday, after traveling from Berlin.
On the agenda will be the nuclear deal with Iran as well as how to push Iranian forces out of Syria.